687161 has 2 divisors, whose sum is σ = 687162. Its totient is φ = 687160.

The previous prime is 687151. The next prime is 687163. The reversal of 687161 is 161786.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 577600 + 109561 = 760^2 + 331^2 .

It is a cyclic number.

It is not a de Polignac number, because 687161 - 2¹⁴ = 670777 is a prime.

Together with 687163, it forms a pair of twin primes.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 687161.

It is not a weakly prime, because it can be changed into another prime (687163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343580 + 343581.

It is an arithmetic number, because the mean of its divisors is an integer number (343581).

2⁶⁸⁷¹⁶¹ is an apocalyptic number.

It is an amenable number.

687161 is a deficient number, since it is larger than the sum of its proper divisors (1).

687161 is an equidigital number, since it uses as much as digits as its factorization.

687161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 29.

The square root of 687161 is about 828.9517476910. The cubic root of 687161 is about 88.2441994759.

It can be divided in two parts, 687 and 161, that added together give a palindrome (848).

The spelling of 687161 in words is "six hundred eighty-seven thousand, one hundred sixty-one".